In the field of consumer electronics, depth sensing technology helps to improve the intelligence level and interaction ability of electronic products and helps intelligent terminals to understand human actions, so that it has become one of the interactive tools between the “real physical world” and the “virtual network world”, which could not only realize innovative applications in the fields of smart TV, smart phones, home appliances, tablet PC, etc., but also be used in intelligent video monitoring, facial identification system, 3D animation, dynamic scene detection and 3D reconstruction such as real-time 3D mapping. In industrial field, there is a wide range of application needs for high-resolution and high-precision 3D depth information in the fields such as auto-aided safe driving, high-speed machining, industrial 3D modeling, 3D printing, medical imaging, Internet of Things 3D visual sensing and robotic control.
The depth sensing technology based on the active vision pattern of structured light (the laser pattern projector actively projects graphics pattern and the image sensor captures continuous images) can more accurately obtain the depth information of the target object or projection space, and compared to the binocular stereo camera, this model that uses encoded structured light to actively calibrate the features of the projection object or projection space, which has advantages of acquiring more stable and reliable depth map information, being less affected by ambient light, and not being affected by object's texture information in the match process. For example, Kinect actively projects the infrared laser speckle images to calibrate features, the infrared camera captures the infrared image sequence, and then the depth sensing chip computes and acquires depth information. However, Kinect uses DoE diffraction to generate the laser speckle image, which is difficult to obtain high-resolution and high-precision depth information and difficult to meet the needs of applications in industrial modeling field, etc., and has unavailable ability to self-correcting the improper depth values or holes. At the same time, the existing technologies of structured light encoding depth sensing and 3D measurement are difficult to acquire real-time high-resolution and high-precision depth information of the target object in the dynamic scene.